1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                             P A R . C H 1 0                              --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 1992-2020, Free Software Foundation, Inc.         --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
17-- for  more details.  You should have  received  a copy of the GNU General --
18-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
19-- http://www.gnu.org/licenses for a complete copy of the license.          --
20--                                                                          --
21-- GNAT was originally developed  by the GNAT team at  New York University. --
22-- Extensive contributions were provided by Ada Core Technologies Inc.      --
23--                                                                          --
24------------------------------------------------------------------------------
25
26pragma Style_Checks (All_Checks);
27--  Turn off subprogram body ordering check. Subprograms are in order
28--  by RM section rather than alphabetical
29
30with Fname.UF; use Fname.UF;
31with Uname;    use Uname;
32
33separate (Par)
34package body Ch10 is
35
36   --  Local functions, used only in this chapter
37
38   function P_Context_Clause    return List_Id;
39   function P_Subunit           return Node_Id;
40
41   function Set_Location return Source_Ptr;
42   --  The current compilation unit starts with Token at Token_Ptr. This
43   --  function determines the corresponding source location for the start
44   --  of the unit, including any preceding comment lines.
45
46   procedure Unit_Display
47     (Cunit      : Node_Id;
48      Loc        : Source_Ptr;
49      SR_Present : Boolean);
50   --  This procedure is used to generate a line of output for a unit in
51   --  the source program. Cunit is the node for the compilation unit, and
52   --  Loc is the source location for the start of the unit in the source
53   --  file (which is not necessarily the Sloc of the Cunit node). This
54   --  output is written to the standard output file for use by gnatchop.
55
56   procedure Unit_Location (Sind : Source_File_Index; Loc : Source_Ptr);
57   --  This routine has the same calling sequence as Unit_Display, but
58   --  it outputs only the line number and offset of the location, Loc,
59   --  using Cunit to obtain the proper source file index.
60
61   -------------------------
62   -- 10.1.1  Compilation --
63   -------------------------
64
65   --  COMPILATION ::= {COMPILATION_UNIT}
66
67   --  There is no specific parsing routine for a compilation, since we only
68   --  permit a single compilation in a source file, so there is no explicit
69   --  occurrence of compilations as such (our representation of a compilation
70   --  is a series of separate source files).
71
72   ------------------------------
73   -- 10.1.1  Compilation unit --
74   ------------------------------
75
76   --  COMPILATION_UNIT ::=
77   --    CONTEXT_CLAUSE LIBRARY_ITEM
78   --  | CONTEXT_CLAUSE SUBUNIT
79
80   --  LIBRARY_ITEM ::=
81   --    private LIBRARY_UNIT_DECLARATION
82   --  | LIBRARY_UNIT_BODY
83   --  | [private] LIBRARY_UNIT_RENAMING_DECLARATION
84
85   --  LIBRARY_UNIT_DECLARATION ::=
86   --    SUBPROGRAM_DECLARATION | PACKAGE_DECLARATION
87   --  | GENERIC_DECLARATION    | GENERIC_INSTANTIATION
88
89   --  LIBRARY_UNIT_RENAMING_DECLARATION ::=
90   --    PACKAGE_RENAMING_DECLARATION
91   --  | GENERIC_RENAMING_DECLARATION
92   --  | SUBPROGRAM_RENAMING_DECLARATION
93
94   --  LIBRARY_UNIT_BODY ::= SUBPROGRAM_BODY | PACKAGE_BODY
95
96   --  Error recovery: cannot raise Error_Resync. If an error occurs, tokens
97   --  are skipped up to the next possible beginning of a compilation unit.
98
99   --  Note: if only configuration pragmas are found, Empty is returned
100
101   --  Note: in syntax-only mode, it is possible for P_Compilation_Unit
102   --  to return strange things that are not really compilation units.
103   --  This is done to help out gnatchop when it is faced with nonsense.
104
105   function P_Compilation_Unit return Node_Id is
106      Scan_State         : Saved_Scan_State;
107      Body_Node          : Node_Id;
108      Specification_Node : Node_Id;
109      Unit_Node          : Node_Id;
110      Comp_Unit_Node     : Node_Id;
111      Name_Node          : Node_Id;
112      Item               : Node_Id;
113      Private_Sloc       : Source_Ptr := No_Location;
114      Config_Pragmas     : List_Id;
115      P                  : Node_Id;
116      SR_Present         : Boolean;
117      No_Body            : Boolean;
118
119      Cunit_Error_Flag : Boolean := False;
120      --  This flag is set True if we have to scan for a compilation unit
121      --  token. It is used to ensure clean termination in such cases by
122      --  not insisting on being at the end of file, and, in the syntax only
123      --  case by not scanning for additional compilation units.
124
125      Cunit_Location : Source_Ptr;
126      --  Location of unit for unit identification output (List_Unit option)
127
128   begin
129      Num_Library_Units := Num_Library_Units + 1;
130
131      --  Set location of the compilation unit if unit list option set
132      --  and we are in syntax check only mode
133
134      if List_Units and then Operating_Mode = Check_Syntax then
135         Cunit_Location := Set_Location;
136      else
137         Cunit_Location := No_Location;
138      end if;
139
140      --  Deal with initial pragmas
141
142      Config_Pragmas := No_List;
143
144      --  If we have an initial Source_Reference pragma, then remember the fact
145      --  to generate an NR parameter in the output line.
146
147      SR_Present := False;
148
149      --  If we see a pragma No_Body, remember not to complain about no body
150
151      No_Body := False;
152
153      if Token = Tok_Pragma then
154         Save_Scan_State (Scan_State);
155         Item := P_Pragma;
156
157         if Item = Error
158           or else Pragma_Name_Unmapped (Item) /= Name_Source_Reference
159         then
160            Restore_Scan_State (Scan_State);
161
162         else
163            SR_Present := True;
164
165            --  If first unit, record the file name for gnatchop use
166
167            if Operating_Mode = Check_Syntax
168              and then List_Units
169              and then Num_Library_Units = 1
170            then
171               Write_Str ("Source_Reference pragma for file """);
172               Write_Name (Full_Ref_Name (Current_Source_File));
173               Write_Char ('"');
174               Write_Eol;
175            end if;
176
177            Config_Pragmas := New_List (Item);
178         end if;
179      end if;
180
181      --  Scan out any configuration pragmas
182
183      while Token = Tok_Pragma loop
184         Save_Scan_State (Scan_State);
185         Item := P_Pragma;
186
187         if Item /= Error and then Pragma_Name_Unmapped (Item) = Name_No_Body
188         then
189            No_Body := True;
190         end if;
191
192         if Item = Error
193           or else
194             not Is_Configuration_Pragma_Name (Pragma_Name_Unmapped (Item))
195         then
196            Restore_Scan_State (Scan_State);
197            exit;
198         end if;
199
200         if Config_Pragmas = No_List then
201            Config_Pragmas := Empty_List;
202
203            if Operating_Mode = Check_Syntax and then List_Units then
204               Write_Str ("Configuration pragmas at");
205               Unit_Location (Current_Source_File, Cunit_Location);
206               Write_Eol;
207            end if;
208         end if;
209
210         Append (Item, Config_Pragmas);
211         Cunit_Location := Set_Location;
212      end loop;
213
214      --  Establish compilation unit node and scan context items
215
216      Comp_Unit_Node := New_Node (N_Compilation_Unit, No_Location);
217      Set_Cunit (Current_Source_Unit, Comp_Unit_Node);
218      Set_Context_Items (Comp_Unit_Node, P_Context_Clause);
219      Set_Aux_Decls_Node
220        (Comp_Unit_Node, New_Node (N_Compilation_Unit_Aux, No_Location));
221
222      if Present (Config_Pragmas) then
223
224         --  Check for case of only configuration pragmas present
225
226         if Token = Tok_EOF
227           and then Is_Empty_List (Context_Items (Comp_Unit_Node))
228         then
229            if Operating_Mode = Check_Syntax then
230               return Empty;
231
232            else
233               Item := First (Config_Pragmas);
234               Error_Msg_N
235                 ("cannot compile configuration pragmas with gcc!", Item);
236               Error_Msg_N
237                 ("\use gnatchop -c to process configuration pragmas!", Item);
238               raise Unrecoverable_Error;
239            end if;
240
241         --  Otherwise configuration pragmas are simply prepended to the
242         --  context of the current unit.
243
244         else
245            Append_List (Context_Items (Comp_Unit_Node), Config_Pragmas);
246            Set_Context_Items (Comp_Unit_Node, Config_Pragmas);
247         end if;
248      end if;
249
250      --  Check for PRIVATE. Note that for the moment we allow this in
251      --  Ada_83 mode, since we do not yet know if we are compiling a
252      --  predefined unit, and if we are then it would be allowed anyway.
253
254      if Token = Tok_Private then
255         Private_Sloc := Token_Ptr;
256         Set_Keyword_Casing (Current_Source_File, Determine_Token_Casing);
257
258         if Style_Check then
259            Style.Check_Indentation;
260         end if;
261
262         Save_Scan_State (Scan_State); -- at PRIVATE
263         Scan; -- past PRIVATE
264
265         if Token = Tok_Separate then
266            Error_Msg_SP ("cannot have private subunits!");
267
268         elsif Token = Tok_Package then
269            Scan; -- past PACKAGE
270
271            if Token = Tok_Body then
272               Restore_Scan_State (Scan_State); -- to PRIVATE
273               Error_Msg_SC ("cannot have private package body!");
274               Scan; -- ignore PRIVATE
275
276            else
277               Restore_Scan_State (Scan_State); -- to PRIVATE
278               Scan; -- past PRIVATE
279               Set_Private_Present (Comp_Unit_Node, True);
280            end if;
281
282         elsif Token = Tok_Procedure
283           or else Token = Tok_Function
284           or else Token = Tok_Generic
285         then
286            Set_Private_Present (Comp_Unit_Node, True);
287         end if;
288      end if;
289
290      --  Loop to find our way to a compilation unit token
291
292      loop
293         exit when Token in Token_Class_Cunit and then Token /= Tok_With;
294
295         exit when Bad_Spelling_Of (Tok_Package)
296           or else Bad_Spelling_Of (Tok_Function)
297           or else Bad_Spelling_Of (Tok_Generic)
298           or else Bad_Spelling_Of (Tok_Separate)
299           or else Bad_Spelling_Of (Tok_Procedure);
300
301         --  Allow task and protected for nice error recovery purposes
302
303         exit when Token = Tok_Task
304           or else Token = Tok_Protected;
305
306         if Token = Tok_With then
307            Error_Msg_SC ("misplaced WITH");
308            Append_List (P_Context_Clause, Context_Items (Comp_Unit_Node));
309
310         elsif Bad_Spelling_Of (Tok_With) then
311            Append_List (P_Context_Clause, Context_Items (Comp_Unit_Node));
312
313         else
314            if Operating_Mode = Check_Syntax and then Token = Tok_EOF then
315
316               --  Do not complain if there is a pragma No_Body
317
318               if not No_Body then
319                  Error_Msg_SC ("??file contains no compilation units");
320               end if;
321
322            else
323               Error_Msg_SC ("compilation unit expected");
324               Cunit_Error_Flag := True;
325               Resync_Cunit;
326            end if;
327
328            --  If we are at an end of file, then just quit, the above error
329            --  message was complaint enough.
330
331            if Token = Tok_EOF then
332               return Error;
333            end if;
334         end if;
335      end loop;
336
337      --  We have a compilation unit token, so that's a reasonable choice for
338      --  determining the standard casing convention used for keywords in case
339      --  it hasn't already been done on seeing a WITH or PRIVATE.
340
341      Set_Keyword_Casing (Current_Source_File, Determine_Token_Casing);
342
343      if Style_Check then
344         Style.Check_Indentation;
345      end if;
346
347      --  Remaining processing depends on particular type of compilation unit
348
349      if Token = Tok_Package then
350
351         --  A common error is to omit the body keyword after package. We can
352         --  often diagnose this early on (before getting loads of errors from
353         --  contained subprogram bodies), by knowing that the file we
354         --  are compiling has a name that requires a body to be found.
355
356         Save_Scan_State (Scan_State);
357         Scan; -- past Package keyword
358
359         if Token /= Tok_Body
360           and then
361             Get_Expected_Unit_Type
362               (File_Name (Current_Source_File)) = Expect_Body
363         then
364            Error_Msg_BC -- CODEFIX
365              ("keyword BODY expected here '[see file name']");
366            Restore_Scan_State (Scan_State);
367            Set_Unit (Comp_Unit_Node, P_Package (Pf_Pbod_Pexp));
368         else
369            Restore_Scan_State (Scan_State);
370            Set_Unit (Comp_Unit_Node, P_Package (Pf_Decl_Gins_Pbod_Rnam_Pexp));
371         end if;
372
373      elsif Token = Tok_Generic then
374         Set_Unit (Comp_Unit_Node, P_Generic);
375
376      elsif Token = Tok_Separate then
377         Set_Unit (Comp_Unit_Node, P_Subunit);
378
379      elsif Token = Tok_Function
380        or else Token = Tok_Not
381        or else Token = Tok_Overriding
382        or else Token = Tok_Procedure
383      then
384         Set_Unit (Comp_Unit_Node, P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Pexp));
385
386         --  A little bit of an error recovery check here. If we just scanned
387         --  a subprogram declaration (as indicated by an SIS entry being
388         --  active), then if the following token is BEGIN or an identifier,
389         --  or a token which can reasonably start a declaration but cannot
390         --  start a compilation unit, then we assume that the semicolon in
391         --  the declaration should have been IS.
392
393         if SIS_Entry_Active then
394
395            if Token = Tok_Begin
396               or else Token = Tok_Identifier
397               or else Token in Token_Class_Deckn
398            then
399               Push_Scope_Stack;
400               Scopes (Scope.Last).Etyp := E_Name;
401               Scopes (Scope.Last).Sloc := SIS_Sloc;
402               Scopes (Scope.Last).Ecol := SIS_Ecol;
403               Scopes (Scope.Last).Lreq := False;
404               SIS_Entry_Active := False;
405
406               --  If we had a missing semicolon in the declaration, then
407               --  change the message to from <missing ";"> to <missing "is">
408
409               if SIS_Missing_Semicolon_Message /= No_Error_Msg then
410                  Change_Error_Text     -- Replace: "missing "";"" "
411                    (SIS_Missing_Semicolon_Message, "missing IS");
412
413               --  Otherwise we saved the semicolon position, so complain
414
415               else
416                  Error_Msg -- CODEFIX
417                    (""";"" should be IS", SIS_Semicolon_Sloc);
418               end if;
419
420               Body_Node := Unit (Comp_Unit_Node);
421               Specification_Node := Specification (Body_Node);
422               Change_Node (Body_Node, N_Subprogram_Body);
423               Set_Specification (Body_Node, Specification_Node);
424               Parse_Decls_Begin_End (Body_Node);
425               Set_Unit (Comp_Unit_Node, Body_Node);
426            end if;
427
428         --  If we scanned a subprogram body, make sure we did not have private
429
430         elsif Private_Sloc /= No_Location
431           and then
432             Nkind (Unit (Comp_Unit_Node)) not in N_Subprogram_Instantiation
433           and then
434             Nkind (Unit (Comp_Unit_Node)) /= N_Subprogram_Renaming_Declaration
435         then
436            Error_Msg ("cannot have private subprogram body", Private_Sloc);
437
438         --  P_Subprogram can yield an abstract subprogram, but this cannot
439         --  be a compilation unit. Treat as a subprogram declaration.
440
441         elsif
442           Nkind (Unit (Comp_Unit_Node)) = N_Abstract_Subprogram_Declaration
443         then
444            Error_Msg_N
445              ("compilation unit cannot be abstract subprogram",
446                 Unit (Comp_Unit_Node));
447
448            Unit_Node :=
449              New_Node (N_Subprogram_Declaration, Sloc (Comp_Unit_Node));
450            Set_Specification (Unit_Node,
451              Specification (Unit (Comp_Unit_Node)));
452            Set_Unit (Comp_Unit_Node, Unit_Node);
453         end if;
454
455      --  Otherwise we have TASK. This is not really an acceptable token,
456      --  but we accept it to improve error recovery.
457
458      elsif Token = Tok_Task then
459         Scan; -- Past TASK
460
461         if Token = Tok_Type then
462            Error_Msg_SP
463              ("task type cannot be used as compilation unit");
464         else
465            Error_Msg_SP
466              ("task declaration cannot be used as compilation unit");
467         end if;
468
469         --  If in check syntax mode, accept the task anyway. This is done
470         --  particularly to improve the behavior of GNATCHOP in this case.
471
472         if Operating_Mode = Check_Syntax then
473            Set_Unit (Comp_Unit_Node, P_Task);
474
475         --  If not in syntax only mode, treat this as horrible error
476
477         else
478            Cunit_Error_Flag := True;
479            return Error;
480         end if;
481
482      else pragma Assert (Token = Tok_Protected);
483         Scan; -- Past PROTECTED
484
485         if Token = Tok_Type then
486            Error_Msg_SP
487              ("protected type cannot be used as compilation unit");
488         else
489            Error_Msg_SP
490              ("protected declaration cannot be used as compilation unit");
491         end if;
492
493         --  If in check syntax mode, accept protected anyway. This is done
494         --  particularly to improve the behavior of GNATCHOP in this case.
495
496         if Operating_Mode = Check_Syntax then
497            Set_Unit (Comp_Unit_Node, P_Protected);
498
499         --  If not in syntax only mode, treat this as horrible error
500
501         else
502            Cunit_Error_Flag := True;
503            return Error;
504         end if;
505      end if;
506
507      --  Here is where locate the compilation unit entity. This is a little
508      --  tricky, since it is buried in various places.
509
510      Unit_Node := Unit (Comp_Unit_Node);
511
512      --  Another error from which it is hard to recover
513
514      if Nkind (Unit_Node) in N_Subprogram_Body_Stub | N_Package_Body_Stub then
515         Cunit_Error_Flag := True;
516         return Error;
517      end if;
518
519      --  Only try this if we got an OK unit
520
521      if Unit_Node /= Error then
522         if Nkind (Unit_Node) = N_Subunit then
523            Unit_Node := Proper_Body (Unit_Node);
524         end if;
525
526         if Nkind (Unit_Node) in N_Generic_Declaration then
527            Unit_Node := Specification (Unit_Node);
528         end if;
529
530         if Nkind (Unit_Node) in N_Package_Declaration
531                               | N_Subprogram_Declaration
532                               | N_Subprogram_Body
533                               | N_Subprogram_Renaming_Declaration
534         then
535            Unit_Node := Specification (Unit_Node);
536
537         elsif Nkind (Unit_Node) = N_Subprogram_Renaming_Declaration then
538            if Ada_Version = Ada_83 then
539               Error_Msg_N
540                 ("(Ada 83) library unit renaming not allowed", Unit_Node);
541            end if;
542         end if;
543
544         if Nkind (Unit_Node) in N_Task_Body
545                               | N_Protected_Body
546                               | N_Task_Type_Declaration
547                               | N_Protected_Type_Declaration
548                               | N_Single_Task_Declaration
549                               | N_Single_Protected_Declaration
550         then
551            Name_Node := Defining_Identifier (Unit_Node);
552
553         elsif Nkind (Unit_Node) in N_Function_Instantiation
554                                  | N_Function_Specification
555                                  | N_Generic_Function_Renaming_Declaration
556                                  | N_Generic_Package_Renaming_Declaration
557                                  | N_Generic_Procedure_Renaming_Declaration
558          or else Nkind (Unit_Node) in N_Package_Body
559                                  | N_Package_Instantiation
560                                  | N_Package_Renaming_Declaration
561                                  | N_Package_Specification
562                                  | N_Procedure_Instantiation
563                                  | N_Procedure_Specification
564         then
565            Name_Node := Defining_Unit_Name (Unit_Node);
566
567         elsif Nkind (Unit_Node) = N_Expression_Function then
568            Error_Msg_SP
569              ("expression function cannot be used as compilation unit");
570            return Comp_Unit_Node;
571
572         --  Anything else is a serious error, abandon scan
573
574         else
575            raise Error_Resync;
576         end if;
577
578         Set_Sloc (Comp_Unit_Node, Sloc (Name_Node));
579         Set_Sloc (Aux_Decls_Node (Comp_Unit_Node), Sloc (Name_Node));
580
581         --  Set Entity field in file table. Easier now that we have name.
582         --  Note that this is also skipped if we had a bad unit
583
584         if Nkind (Name_Node) = N_Defining_Program_Unit_Name then
585            Set_Cunit_Entity
586              (Current_Source_Unit, Defining_Identifier (Name_Node));
587         else
588            Set_Cunit_Entity (Current_Source_Unit, Name_Node);
589         end if;
590
591         Set_Unit_Name
592           (Current_Source_Unit, Get_Unit_Name (Unit (Comp_Unit_Node)));
593
594      --  If we had a bad unit, make sure the fatal flag is set in the file
595      --  table entry, since this is surely a fatal error and also set our
596      --  flag to inhibit the requirement that we be at end of file.
597
598      else
599         Cunit_Error_Flag := True;
600         Set_Fatal_Error (Current_Source_Unit, Error_Detected);
601      end if;
602
603      --  Clear away any missing semicolon indication, we are done with that
604      --  unit, so what's done is done, and we don't want anything hanging
605      --  around from the attempt to parse it.
606
607      SIS_Entry_Active := False;
608
609      --  Scan out pragmas after unit
610
611      while Token = Tok_Pragma loop
612         Save_Scan_State (Scan_State);
613
614         --  If we are in syntax scan mode allowing multiple units, then start
615         --  the next unit if we encounter a configuration pragma, or a source
616         --  reference pragma. We take care not to actually scan the pragma in
617         --  this case (we don't want it to take effect for the current unit).
618
619         if Operating_Mode = Check_Syntax then
620            Scan;  -- past Pragma
621
622            if Token = Tok_Identifier
623              and then
624                (Is_Configuration_Pragma_Name (Token_Name)
625                   or else Token_Name = Name_Source_Reference)
626            then
627               Restore_Scan_State (Scan_State); -- to Pragma
628               exit;
629            end if;
630         end if;
631
632         --  Otherwise eat the pragma, it definitely belongs with the
633         --  current unit, and not with the following unit.
634
635         Restore_Scan_State (Scan_State); -- to Pragma
636         P := P_Pragma;
637
638         if No (Pragmas_After (Aux_Decls_Node (Comp_Unit_Node))) then
639            Set_Pragmas_After
640              (Aux_Decls_Node (Comp_Unit_Node), New_List);
641         end if;
642
643         Append (P, Pragmas_After (Aux_Decls_Node (Comp_Unit_Node)));
644      end loop;
645
646      --  Cancel effect of any outstanding pragma Warnings (Off)
647
648      Set_Warnings_Mode_On (Scan_Ptr);
649
650      --  Ada 83 error checks
651
652      if Ada_Version = Ada_83 then
653
654         --  Check we did not with any child units
655
656         Item := First (Context_Items (Comp_Unit_Node));
657         while Present (Item) loop
658            if Nkind (Item) = N_With_Clause
659              and then Nkind (Name (Item)) /= N_Identifier
660            then
661               Error_Msg_N ("(Ada 83) child units not allowed", Item);
662            end if;
663
664            Next (Item);
665         end loop;
666
667         --  Check that we did not have a PRIVATE keyword present
668
669         if Private_Present (Comp_Unit_Node) then
670            Error_Msg
671              ("(Ada 83) private units not allowed", Private_Sloc);
672         end if;
673      end if;
674
675      --  If no serious error, then output possible unit information line
676      --  for gnatchop if we are in syntax only, list units mode.
677
678      if not Cunit_Error_Flag
679        and then List_Units
680        and then Operating_Mode = Check_Syntax
681      then
682         Unit_Display (Comp_Unit_Node, Cunit_Location, SR_Present);
683      end if;
684
685      --  And now we should be at the end of file
686
687      if Token /= Tok_EOF then
688
689         --  If we already had to scan for a compilation unit, then don't
690         --  give any further error message, since it just seems to make
691         --  things worse, and we already gave a serious error message.
692
693         if Cunit_Error_Flag then
694            null;
695
696         --  If we are in check syntax mode, then we allow multiple units
697         --  so we just return with Token not set to Tok_EOF and no message.
698
699         elsif Operating_Mode = Check_Syntax then
700            return Comp_Unit_Node;
701
702         --  We also allow multiple units if we are in multiple unit mode
703
704         elsif Multiple_Unit_Index /= 0 then
705
706            --  Skip tokens to end of file, so that the -gnatl listing
707            --  will be complete in this situation, but no need to parse
708            --  the remaining units; no style checking either.
709
710            declare
711               Save_Style_Check : constant Boolean := Style_Check;
712
713            begin
714               Style_Check := False;
715
716               while Token /= Tok_EOF loop
717                  Scan;
718               end loop;
719
720               Style_Check := Save_Style_Check;
721            end;
722
723            return Comp_Unit_Node;
724
725         --  Otherwise we have an error. We suppress the error message
726         --  if we already had a fatal error, since this stops junk
727         --  cascaded messages in some situations.
728
729         else
730            if Fatal_Error (Current_Source_Unit) /= Error_Detected then
731               if Token in Token_Class_Cunit then
732                  Error_Msg_SC
733                    ("end of file expected, " &
734                     "file can have only one compilation unit");
735               else
736                  Error_Msg_SC ("end of file expected");
737               end if;
738            end if;
739         end if;
740
741         --  Skip tokens to end of file, so that the -gnatl listing
742         --  will be complete in this situation, but no error checking
743         --  other than that provided at the token level.
744
745         while Token /= Tok_EOF loop
746            Scan;
747         end loop;
748
749         return Error;
750
751      --  Normal return (we were at the end of file as expected)
752
753      else
754         return Comp_Unit_Node;
755      end if;
756
757   exception
758
759      --  An error resync is a serious bomb, so indicate result unit no good
760
761      when Error_Resync =>
762         Set_Fatal_Error (Current_Source_Unit, Error_Detected);
763         return Error;
764   end P_Compilation_Unit;
765
766   --------------------------
767   -- 10.1.1  Library Item --
768   --------------------------
769
770   --  Parsed by P_Compilation_Unit (10.1.1)
771
772   --------------------------------------
773   -- 10.1.1  Library Unit Declaration --
774   --------------------------------------
775
776   --  Parsed by P_Compilation_Unit (10.1.1)
777
778   ------------------------------------------------
779   -- 10.1.1  Library Unit Renaming Declaration  --
780   ------------------------------------------------
781
782   --  Parsed by P_Compilation_Unit (10.1.1)
783
784   -------------------------------
785   -- 10.1.1  Library Unit Body --
786   -------------------------------
787
788   --  Parsed by P_Compilation_Unit (10.1.1)
789
790   ------------------------------
791   -- 10.1.1  Parent Unit Name --
792   ------------------------------
793
794   --  Parsed (as a name) by its parent construct
795
796   ----------------------------
797   -- 10.1.2  Context Clause --
798   ----------------------------
799
800   --  CONTEXT_CLAUSE ::= {CONTEXT_ITEM}
801
802   --  CONTEXT_ITEM ::= WITH_CLAUSE | USE_CLAUSE | WITH_TYPE_CLAUSE
803
804   --  WITH_CLAUSE ::=
805   --  [LIMITED] [PRIVATE]  with library_unit_NAME {,library_unit_NAME};
806   --  Note: the two qualifiers are Ada 2005 extensions.
807
808   --  WITH_TYPE_CLAUSE ::=
809   --    with type type_NAME is access; | with type type_NAME is tagged;
810   --  Note: this form is obsolete (old GNAT extension).
811
812   --  Error recovery: Cannot raise Error_Resync
813
814   function P_Context_Clause return List_Id is
815      Item_List   : List_Id;
816      Has_Limited : Boolean := False;
817      Has_Private : Boolean := False;
818      Scan_State  : Saved_Scan_State;
819      With_Node   : Node_Id;
820      First_Flag  : Boolean;
821
822   begin
823      Item_List := New_List;
824
825      --  Get keyword casing from WITH keyword in case not set yet
826
827      if Token = Tok_With then
828         Set_Keyword_Casing (Current_Source_File, Determine_Token_Casing);
829      end if;
830
831      --  Loop through context items
832
833      loop
834         if Style_Check then
835            Style.Check_Indentation;
836         end if;
837
838         --  Gather any pragmas appearing in the context clause
839
840         P_Pragmas_Opt (Item_List);
841
842         --  Processing for WITH clause
843
844         --  Ada 2005 (AI-50217, AI-262): First check for LIMITED WITH,
845         --  PRIVATE WITH, or both.
846
847         if Token = Tok_Limited then
848            Has_Limited := True;
849            Has_Private := False;
850            Scan; -- past LIMITED
851
852            --  In the context, LIMITED can only appear in a with_clause
853
854            if Token = Tok_Private then
855               Has_Private := True;
856               Scan;  -- past PRIVATE
857            end if;
858
859            if Token /= Tok_With then
860               Error_Msg_SC -- CODEFIX
861                 ("unexpected LIMITED ignored");
862            end if;
863
864            Error_Msg_Ada_2005_Extension ("`LIMITED WITH`");
865
866         elsif Token = Tok_Private then
867            Has_Limited := False;
868            Has_Private := True;
869            Save_Scan_State (Scan_State);
870            Scan;  -- past PRIVATE
871
872            if Token /= Tok_With then
873
874               --  Keyword is beginning of private child unit
875
876               Restore_Scan_State (Scan_State); -- to PRIVATE
877               return Item_List;
878            end if;
879
880            Error_Msg_Ada_2005_Extension ("`PRIVATE WITH`");
881
882         else
883            Has_Limited := False;
884            Has_Private := False;
885         end if;
886
887         if Token = Tok_With then
888            Scan; -- past WITH
889
890            if Token = Tok_Type then
891
892               --  WITH TYPE is an obsolete GNAT specific extension
893
894               Error_Msg_SP ("`WITH TYPE` is an obsolete 'G'N'A'T extension");
895               Error_Msg_SP ("\use Ada 2005 `LIMITED WITH` clause instead");
896
897               Scan;  -- past TYPE
898
899               T_Is;
900
901               if Token = Tok_Tagged then
902                  Scan;
903
904               elsif Token = Tok_Access then
905                  Scan;
906
907               else
908                  Error_Msg_SC ("expect tagged or access qualifier");
909               end if;
910
911               TF_Semicolon;
912
913            else
914               First_Flag := True;
915
916               --  Loop through names in one with clause, generating a separate
917               --  N_With_Clause node for each name encountered.
918
919               loop
920                  With_Node := New_Node (N_With_Clause, Token_Ptr);
921                  Append (With_Node, Item_List);
922
923                  --  Note that we allow with'ing of child units, even in
924                  --  Ada 83 mode, since presumably if this is not desired,
925                  --  then the compilation of the child unit itself is the
926                  --  place where such an "error" should be caught.
927
928                  Set_Name (With_Node, P_Qualified_Simple_Name);
929                  if Name (With_Node) = Error then
930                     Remove (With_Node);
931                  end if;
932
933                  Set_First_Name (With_Node, First_Flag);
934                  Set_Limited_Present (With_Node, Has_Limited);
935                  Set_Private_Present (With_Node, Has_Private);
936                  First_Flag := False;
937
938                  --  All done if no comma
939
940                  exit when Token /= Tok_Comma;
941
942                  --  If comma is followed by compilation unit token
943                  --  or by USE, or PRAGMA, then it should have been a
944                  --  semicolon after all
945
946                  Save_Scan_State (Scan_State);
947                  Scan; -- past comma
948
949                  if Token in Token_Class_Cunit
950                    or else Token = Tok_Use
951                    or else Token = Tok_Pragma
952                  then
953                     Restore_Scan_State (Scan_State);
954                     exit;
955                  end if;
956               end loop;
957
958               Set_Last_Name (With_Node, True);
959               TF_Semicolon;
960            end if;
961
962         --  Processing for USE clause
963
964         elsif Token = Tok_Use then
965            P_Use_Clause (Item_List);
966
967         --  Anything else is end of context clause
968
969         else
970            exit;
971         end if;
972      end loop;
973
974      return Item_List;
975   end P_Context_Clause;
976
977   --------------------------
978   -- 10.1.2  Context Item --
979   --------------------------
980
981   --  Parsed by P_Context_Clause (10.1.2)
982
983   -------------------------
984   -- 10.1.2  With Clause --
985   -------------------------
986
987   --  Parsed by P_Context_Clause (10.1.2)
988
989   -----------------------
990   -- 10.1.3  Body Stub --
991   -----------------------
992
993   --  Subprogram stub parsed by P_Subprogram (6.1)
994   --  Package stub parsed by P_Package (7.1)
995   --  Task stub parsed by P_Task (9.1)
996   --  Protected stub parsed by P_Protected (9.4)
997
998   ----------------------------------
999   -- 10.1.3  Subprogram Body Stub --
1000   ----------------------------------
1001
1002   --  Parsed by P_Subprogram (6.1)
1003
1004   -------------------------------
1005   -- 10.1.3  Package Body Stub --
1006   -------------------------------
1007
1008   --  Parsed by P_Package (7.1)
1009
1010   ----------------------------
1011   -- 10.1.3  Task Body Stub --
1012   ----------------------------
1013
1014   --  Parsed by P_Task (9.1)
1015
1016   ---------------------------------
1017   -- 10.1.3  Protected Body Stub --
1018   ---------------------------------
1019
1020   --  Parsed by P_Protected (9.4)
1021
1022   ---------------------
1023   -- 10.1.3  Subunit --
1024   ---------------------
1025
1026   --  SUBUNIT ::= separate (PARENT_UNIT_NAME) PROPER_BODY
1027
1028   --  PARENT_UNIT_NAME ::= NAME
1029
1030   --  The caller has checked that the initial token is SEPARATE
1031
1032   --  Error recovery: cannot raise Error_Resync
1033
1034   function P_Subunit return Node_Id is
1035      Subunit_Node : Node_Id;
1036      Body_Node    : Node_Id;
1037
1038   begin
1039      Subunit_Node := New_Node (N_Subunit, Token_Ptr);
1040      Body_Node := Error; -- in case no good body found
1041      Scan; -- past SEPARATE;
1042
1043      U_Left_Paren;
1044      Set_Name (Subunit_Node, P_Qualified_Simple_Name);
1045      U_Right_Paren;
1046
1047      Ignore (Tok_Semicolon);
1048
1049      if Token = Tok_Function
1050        or else Token = Tok_Not
1051        or else Token = Tok_Overriding
1052        or else Token = Tok_Procedure
1053      then
1054         Body_Node := P_Subprogram (Pf_Pbod_Pexp);
1055
1056      elsif Token = Tok_Package then
1057         Body_Node := P_Package (Pf_Pbod_Pexp);
1058
1059      elsif Token = Tok_Protected then
1060         Scan; -- past PROTECTED
1061
1062         if Token = Tok_Body then
1063            Body_Node := P_Protected;
1064         else
1065            Error_Msg_AP ("BODY expected");
1066            return Error;
1067         end if;
1068
1069      elsif Token = Tok_Task then
1070         Scan; -- past TASK
1071
1072         if Token = Tok_Body then
1073            Body_Node := P_Task;
1074         else
1075            Error_Msg_AP ("BODY expected");
1076            return Error;
1077         end if;
1078
1079      else
1080         Error_Msg_SC ("proper body expected");
1081         return Error;
1082      end if;
1083
1084      Set_Proper_Body  (Subunit_Node, Body_Node);
1085      return Subunit_Node;
1086   end P_Subunit;
1087
1088   ------------------
1089   -- Set_Location --
1090   ------------------
1091
1092   function Set_Location return Source_Ptr is
1093      Physical   : Boolean;
1094      Loc        : Source_Ptr;
1095      Scan_State : Saved_Scan_State;
1096
1097   begin
1098      --  A special check. If the first token is pragma, and this is a
1099      --  Source_Reference pragma, then do NOT eat previous comments, since
1100      --  the Source_Reference pragma is required to be the first line in
1101      --  the source file.
1102
1103      if Token = Tok_Pragma then
1104         Save_Scan_State (Scan_State);
1105         Scan; --  past Pragma
1106
1107         if Token = Tok_Identifier
1108           and then Token_Name = Name_Source_Reference
1109         then
1110            Restore_Scan_State (Scan_State);
1111            return Token_Ptr;
1112         end if;
1113
1114         Restore_Scan_State (Scan_State);
1115      end if;
1116
1117      --  Otherwise acquire previous comments and blank lines
1118
1119      if Prev_Token = No_Token then
1120         return Source_First (Current_Source_File);
1121
1122      else
1123         Loc := Prev_Token_Ptr;
1124         loop
1125            exit when Loc = Token_Ptr;
1126
1127            --  Should we worry about UTF_32 line terminators here
1128
1129            if Source (Loc) in Line_Terminator then
1130               Skip_Line_Terminators (Loc, Physical);
1131               exit when Physical;
1132            end if;
1133
1134            Loc := Loc + 1;
1135         end loop;
1136
1137         return Loc;
1138      end if;
1139   end Set_Location;
1140
1141   ------------------
1142   -- Unit_Display --
1143   ------------------
1144
1145   --  The format of the generated line, as expected by GNATCHOP is
1146
1147   --    Unit {unit} line {line}, file offset {offs} [, SR], file name {file}
1148
1149   --  where
1150
1151   --     {unit}     unit name with terminating (spec) or (body)
1152   --     {line}     starting line number
1153   --     {offs}     offset to start of text in file
1154   --     {file}     source file name
1155
1156   --  The SR parameter is present only if a source reference pragma was
1157   --  scanned for this unit. The significance is that gnatchop should not
1158   --  attempt to add another one.
1159
1160   procedure Unit_Display
1161     (Cunit      : Node_Id;
1162      Loc        : Source_Ptr;
1163      SR_Present : Boolean)
1164   is
1165      Unum : constant Unit_Number_Type    := Get_Cunit_Unit_Number (Cunit);
1166      Sind : constant Source_File_Index   := Source_Index (Unum);
1167      Unam : constant Unit_Name_Type      := Unit_Name (Unum);
1168
1169   begin
1170      if List_Units then
1171         Write_Str ("Unit ");
1172         Write_Unit_Name (Unit_Name (Unum));
1173         Unit_Location (Sind, Loc);
1174
1175         if SR_Present then
1176            Write_Str (", SR");
1177         end if;
1178
1179         Write_Str (", file name ");
1180         Write_Name (Get_File_Name (Unam, Nkind (Unit (Cunit)) = N_Subunit));
1181         Write_Eol;
1182      end if;
1183   end Unit_Display;
1184
1185   -------------------
1186   -- Unit_Location --
1187   -------------------
1188
1189   procedure Unit_Location (Sind : Source_File_Index; Loc : Source_Ptr) is
1190      Line : constant Logical_Line_Number := Get_Logical_Line_Number (Loc);
1191      --  Should the above be the physical line number ???
1192
1193   begin
1194      Write_Str (" line ");
1195      Write_Int (Int (Line));
1196
1197      Write_Str (", file offset ");
1198      Write_Int (Int (Loc) - Int (Source_First (Sind)));
1199   end Unit_Location;
1200
1201end Ch10;
1202